An adenylyl cyclase that functions during late development of Dictyostelium

Development. 1999 Dec;126(23):5463-71. doi: 10.1242/dev.126.23.5463.

Abstract

A variety of extracellular signals lead to the accumulation of cAMP which can act as a second message within cells by activating protein kinase A (PKA). Expression of many of the essential developmental genes in Dictyostelium discoideum are known to depend on PKA activity. Cells in which the receptor-coupled adenylyl cyclase gene, acaA, is genetically inactivated grow well but are unable to develop. Surprisingly, acaA(-) mutant cells can be rescued by developing them in mixtures with wild-type cells, suggesting that another adenylyl cyclase is present in developing cells that can provide the internal cAMP necessary to activate PKA. However, the only other known adenylyl cyclase gene in Dictyostelium, acgA, is only expressed during germination of spores and plays no role in the formation of fruiting bodies. By screening morphological mutants generated by Restriction Enzyme Mediated Integration (REMI) we discovered a novel adenylyl cyclase gene, acrA, that is expressed at low levels in growing cells and at more than 25-fold higher levels during development. Growth and development up to the slug stage are unaffected in acrA(-) mutant strains but the cells make almost no viable spores and produce unnaturally long stalks. Adenylyl cyclase activity increases during aggregation, plateaus during the slug stage and then increases considerably during terminal differentiation. The increase in activity following aggregation fails to occur in acrA(-) cells. As long as ACA is fully active, ACR is not required until culmination but then plays a critical role in sporulation and construction of the stalk.

Publication types

  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenylyl Cyclases / genetics*
  • Adenylyl Cyclases / metabolism*
  • Amino Acid Sequence
  • Animals
  • Bacterial Proteins / genetics
  • Cloning, Molecular
  • Dictyostelium / classification
  • Dictyostelium / genetics
  • Dictyostelium / growth & development*
  • Gene Expression Regulation, Developmental
  • Histidine Kinase
  • Molecular Chaperones*
  • Molecular Sequence Data
  • Mutagenesis
  • Mutation
  • Protein Kinases / genetics
  • Protein Kinases / metabolism
  • Protozoan Proteins / genetics*
  • Protozoan Proteins / metabolism
  • Sequence Homology, Amino Acid
  • Species Specificity

Substances

  • Bacterial Proteins
  • Molecular Chaperones
  • Protozoan Proteins
  • SpiA protein, Salmonella typhimurium
  • CsaA protein, Bacillus subtilis
  • Protein Kinases
  • Histidine Kinase
  • Adenylyl Cyclases

Associated data

  • GENBANK/AF153362